1 Reply Latest reply on Jun 28, 2012 9:44 AM by JFFulcrum

    one-way speed of single x1 PCIe slot with G41 chipset

    Paul Mitchell

      The block diagram here:




      500 MB/s each x1


      But, is this speed for one direction only, or

      for both directions combined?


      In other words, if I install an x1 PCIe 2.0 RAID controller e.g.

      Newegg.com - HighPoint RocketRAID 620 PCI-Express 2.0 x1 SATA III (6.0Gb/s) Controller Card

      is the maximum upstream bandwidth limited to 250 MB/s

      even though each SATA channel is rated at 300 MB/s?


      It would help if the chipset block diagram indicated

      the PCI-Express Generation for the x1 slot.


      The block diagram does indicate PCI Express 1.1 for the x16 slot.


      If the x1 slot is also PCI Express 1.1, THEN the one-way

      bandwidth of that x1 slot is 250 MB/second, correct?


      Please confirm or correct the above.


      RSVP and ... THANKS!




        • 1. Re: one-way speed of single x1 PCIe slot with G41 chipset

          Yes, in PCI-E 1.x versions each lane have 250 MB/s speed for each direction, 500 combined.


          For SATA channels 300 MB/s - such speeds per channel on regular basis are reachable only with premium-class SSDs. For traditional HDDs even an enterprise 15K rpm models is practically capable for about 100-120 MB/s sustained rate at best - so dual-channel controller without dedicated memory buffer is not bus speed limited.